This invention relates generally as indicated to a combination machine tool apparatus and pallet changing system which utilizes a single pallet changer to change both work pieces and tooling at two separate stations (locations) on a machine tool. The pallet changing system also desirably includes a docking assembly for receiving pallets containing either work pieces or tooling for transfer both to and from the pallet changer as well as to and from a transport vehicle having a lift table assembly for lifting the pallets onto and off the docking assembly.
The use of a single pallet changer to transfer both work piece pallets and tool pallets between a work piece machining station on a machine tool and one or more storage areas remote from the machine tool is generally known. In such a system, the tool pallet must be positioned at the work piece machining station to permit the tools to be transferred by the machine spindle from the pallet, one at a time, to a tool storage station which is also accessible to the machine spindle. This has the disadvantage that the work piece pallet must be removed from the work piece machining station before the tool pallet can be moved into position and vice versa. Accordingly, no machining operation can be performed on the work piece as long as tools are being transferred to and from the tool storage on the machine tool.
It is also generally known to provide a common docking station for receiving both work piece pallets and tool pallets for transfer onto a pallet changer and return. It is also generally known to use a transport vehicle such as an automatic guided vehicle (AGV) to transport the pallets to the docking station for transfer onto the docking station or for picking up the pallets and returning same to one or more pallet staging (storage) areas remote from the machine tool. However, there is a need for a more effective way of raising and lowering the pallets at the docking station into and out of coaxial alignment with the pallet changer.